Battery charging thermostat



May 15, 1945. B. F. w. HEYER '2,376,056

BATTERY CHARGING THERMOSTAT ZM @5mm v www@ May 15, 1945. B F w HEYER 2,376,056

BATTERY CHARGING vTHERMOSTAT Filed Aug. 17, 1942 2 Sheets-Sheet 2 y 32 /fe mm1' /3 W (slum Syvum/nm Patented May `15,1945

Afuturi-:D vs 'rli'rizs PATENT OFFICE BATTERY CHARGING THERMOSTAT Benjamin F. W. Heyer, Tenafiy, N. J pplication August 17, 1942, Serial No. 455,113

isiciai'ms. wrm- 311) -f ing therethrough. Obviously;` the best indicationof the temperature of the battery being charged is the temperature of the electrolyte asthis is in immediate contact with the plates, a'nd the temperature thereof will correspond to the tem- 'perature ofV the essential elements of the battery.

It is also important that'the battery be charged as much as possible lup, tothe temperature limit above which damage to the battery will result, without exceeding such limit- Consequently, any thermostatic control device must be very accurate so as to obtain the maximum charge and yet avoid damage to the battery. Thermostats heretofore constructed for this purpose have not been as accurate as is desired and up until the present there has been no device available for accomplishing the exact control of the charging current relative to Vthe"` battery temperature to enablethe maximumcharging of a battery up to the critical temperature ofthe battery. i

An object of this invention is to provide a thermostatic switch for controlling 'the charging of a battery which will avoid the disadvantages of the prior art.v

Another 'object of this a thermostatic switch for controlling the charging of batteries which is adapted tov be immersed invention ds vto provide nthe'lelectrolyte vof the battery and is highly" sensitive to temperature changes'to enable the' maximum charge to be introduced into the battery without exceeding predetermined temperature limits;

A- further object of this invention is to provide a thermostatically actuated switdh which can be easily and accurately adjusted for operaticg at predetermined temperatures -and will mai ain such adjustment. y -V Still another object of this invention is to provide a thermostatically controlled switch' which comprises a housing having a thermostat mountedonone endthereof and provided with a bulb forfimmersion in Jthe electrolyte -of a battery t befcharged, a switch actuated by said thermostat' and lenclosed within said housing, said bulb being encased in an acid resisting heat conductive .of Figure L ber sheath sealed to the heat conducting sheath and to said housing. A still further object of this invention is to provide a tool for adjusting a thermostatic switch constructed in accordance with the present invention and equipped with means for indicating when a proper adjustment has been obtained.

The present invention also has for an objectv a thermostatically controlled switch for use in battery charging which comprises a housing having an interiorly threaded portion, a support adjustably enthreaded insaid housing and carrying a"switch mechanism, a thermostat mounted in said housing and having a. movable member for actuating` said switch, and means for adjusting the position of said support axially within said vhousing relatively to the movable member of the thermostat.

With ythese and other-objects in view, the present invention resides iny the parts and combinations hereinafter illustrated and described.

Figure 2 is a sectional view taken on line 2-2A of Figure 1. t l 1 Figure 3 is a sectional view taken on line 3-3 ofFigurefl. f y p Figure 4 is a sectional view taken on line 4 4 Figure 5 is a; fragmentary sectional-view taken on line 5-,5 of Figure. 1.- J i 'l Figure 6y is \a perspective view of the switch `support embodied in the 'present invention.

Figure 7 is a diagrammatic representation of a thermostatic switch constructedin accordance wrench provided withl a. testing circuit.

- sheath'andsaid housing being encased in a rub- 55 Figurey 8 is a fragmentary sectional view of the wrench and thermostat taken on line 8-8 of Figure '7. I l

A thermostatic switch embodying-the principles of the present invention as illustrated in the drawings omprises a housing I which is fn the form of a tube obsteel or other suitable material having a portion of the interior surface thereof adjacent one end provided with screw threads v2.

for athermostat tobe mounted therein. e. 'y It iS essential to the present invention tha to be immersed in a liquid such as the electrolyte of a battery the temperature of which is to aiiect the thermostat. Bulb 1 may be filled with turpentine or other suitable material which has an. expansion coeicient suitable for the purpose. The upper end of thethermostat comprises a bellows 8 to the free end of which is secured a movable member in the form of a pusher rod 9. Upon expansion of the liquid within the bulb 1, the bellows is caused to expand and in turn the movable member 9 is displaced axially of the housing I.

Positioned in the upper end of the housing I suitable material the outer circumference of which is threaded to cooperate with thethreads 2 in the housing I. MountedL onl the support disc Ill is a switch in the form of a. contact spring element I I which is secured to the disc by means of studs I2 and' I3. A disc or plate of insulating material fI4 is interposed between the body I0 and the spring I I. The studs I2 and I3 are in-" sulated from the disc I by means of sleeves I5 and I6 of insulating material so that there is no electrical contact between the studs I2 and I3 [housingA I is the bulb 1 of the thermostat whichis adapted ,is a cyiindricai body ordisc In of Steel or other and the disc I0.' Studs 2 and I3 are provided with heads I1 and I8 of enlarged diameter from which extend the terminal posts I9 and 20. In-

terposed between the head I1 and the disc I4 is. the iixed end of spring I I and a pair of metal washers 2l to insure a conductive connection between spring II/ and the head I1. The opening in the fixed end of spring II through which the stud I3 extends is of a diameter larger than that of the stud and may be filled with a ring of insulation to insulate the spring I I from stud I3, An insulating disc or washer 22 lies directly on spring I I and serves to insulate spring I I from the head I8 and any intervening metal washers.

On the under side of the body I0, washers oi insulation 23 and 24 are mounted on studs I2 and I3. A metal washer 25 is positioned on stud I2 and a jumper or conductor strip 26 is posiat various predetermined temperatures.

thermostat. To enable the pusher rod to actuate the spring element II to move the movable contact I6 away from the fixed contact I1, the disc IB is provided with a central opening 29 through which the rod 9 extends. To avoid conductive contact between the spring element II and the pusher rod 9, the latter is provided with a bore in the end which passes through the central opening 29 and` in which is mounted an insulating plug 30 which serves to make actual contact with the spring I I.

When the threaded body Ill is in a position whereby the insulating element 3U of the pusher rod 9 is in engagement with the spring II, heat- 'mg of the thermostat bulb 1 will cause the liquid therein to expand and this in turn will eect a displacement of the pusher rod 9 and will cause the spring I I to be displaced to separate the contacts 21 and 28. By adjusting the axial position of the body I0 and the spring II in the housing 2 relative to the end of the pusher rod, the separation of the contacts 21 and 28 will take place To return the bellows to its normal position upon cooling of bulb 1, a spring 3| is provided.

The threads 2 in the inner surface of the housing I extend inwardly of the tube a suiiicient distance from the upper end thereof to enable the position of the washer I0 to be adjusted in the housing to obtain separation of the contacts within a temperature range through which the device is to be used.

Since the thermostatically actuated switch in accordance with the present invention will be subjected to mechanical shocks in use, the posi.-

tion of the body I0 within the housing may be accidentally varied. To overcome this, the present invention provides means carried by the body ID for frictionally engaging the threads 2 and thereby fr ictionally locking the body I0 in adjusted positions within the housing I. The frictional means found to-.be particularly suitable is, as shown in the several figures of the drawings, in the form of the liber plate or washer I4.

This plate is made to project beyond the pe.- ripheral edge of body I0 and is larger than the i internal threaded portion oi the housing I, so

tioned on stud I3. Strip 26 serves to connect stud I3 to a fixed contact 21 which is rigidly and insulatedly mounted in the disc I 0. The lower ends of studs I2 and I3 and contact 21 are peened to rivet the assembly securely together.l

This arrangement of structure is clearly illustrated in Figure of the drawings. The free end of the spring element II is provided wlth a contact 223 cooperates with the iixed contact 21.

that whenI the body I0 is screwed into the housing il, partial threads will lbe pressed into the projected portions of the plate I4. 'I'his puts a heavy drag or friction on the turning of the body III so that it will remain wherever it is set. No amount of use orvibration will cause the body I Il to be accidentally rotated within the housing. This friction lock enables the body I0 to be more easily adusted in a manner which is quicker and easier than if set screws were used to hold the body in adjusted position.

In actual use.. the plate I4 is made in the form of a disc with three lugs spaced substantially apart and projecting beyond the peripheral portion of the body I0. It will be noted that by providing only three lugs 32 spaced 90 apart there is no projecting lug on one side of the plate I4. The effect o! this construction is for the projecting lugs 32 to vforce the threaded body I0 on the side where there are no lugs/32 against the threads 2 within the housing, thus locking the tightly pressed threads of the body Ill with the threads 2 of thel housing Aunder tension. The eilect of the lugs 32 into .which the threads of the housing cut is to place considerable friction on these parts which serve to prevent rotation of the body I0 within the housing I. ,This construction enables the body l0 to be'I adjusted to 4any desired position within the housing I and be frictionally retained in the adjusted position.

Although three lugs 32, positioned 90 apart are effective, it is not indispensable tothe present invention as a locking action will be provided regardless of the number of lugs, and as a matter of fact even wherr the engagement between theedge of plate I4 and the threads of the housing I is continuous throughout the circumference of the plate. y

In assembling the body I0 Within the housing I, the body is screwed into the same Vby means o1 wrench 33 which is provided with sockets to receive the upper portions of the studs I2 and I3. As illustrated in Figure 8 of the drawings the wrench 33 comprises in insulated body member having tubes 34 and 35 positioned therein tov receive the upper'parts I9 and 20 of the studs I2 and I3. The lower ends of the tubes 34 and 35 are enlarged to form sockets to receive the heads I1.and I 8 of the studs I2 and I3.

The `tubes 34 and 35 are constructed of metal and are connected to conductors 36 and 31 which form part of a test circuit including a battery* 38 and a lamp 39. In the form of' switch illustrated in the drawings, the contacts 21 and`28 are -normally engaged and are adapted to be opened when the temperature of the electrolyte is suiiicient to cause the thermostat to operate. Thus.. the test circuit including the battery 39 and `35i will be completed through the tubes 34 and 35 and the contacts 21 and 28 of the switch.

In adjustingthe position of body III, the .bulb

1 is -immersed in the test bath 40 which is at the temperature at which the switch Jreopen and body I 0 isI moved into the housing IA until the light 39 is extinguiqshed by reason of the element 30 engaging the spring II and causingacid-proof rubber cement is forced between the sheath and the thermostat so that at the juncture of the cable 4I, strain relief 42, and closure 43, a seal 46 .is provided. Also, at the juncture of the lower end of the housing I and the lead sheath 44, another seal 41 is provided. These seals are so formed as to prevent any acid reaching the metal parts of the thermostat and its housing.`

A rubber baille 48 is mounted over the lower end of the rubber sheath and is retained in place by a bead 49. This baille will prevent excessive spraying of acid from the filler opening -thermostat construction which avoids the prior art disadvantages and which is easily made and adjusted.

I claim:

1. A Vcontrol switch comprising a housing element having a bore therein the inner cylindrical surface of whichis threaded, a support element having a threaded external cylindrical sur.- face threadedly mounted in said bore, a switch assembly having a movable member and carried by said threaded support element, an actuating member carried by said housing for actuating the movable member of said switch assembly, said threadedsupport element being rotatably adjustable in said threaded boreJlfor axial displacement relative to said actuating member, and means carried by one element and frictionally engaging the threaded surface of the other to frictionally restrain said elements against relative movement.

2. A control switch comprising a housing having a threaded bore therein, a threaded support i threadedly mounted in said bore,` a -switch assembly having a movable element and carried by said threaded support, an actuating element 'carried by said housing for actuating the movable element of said switch assembly, said threaded supthrough a strain relief 42 which is mounted in an opening within a closure 43 which is securedl of an alloy containing approximately 6% anti-v mony and the balance lead.

To protect the other parts of the thermostat including the housing I, a sheath 45 of rubber is snugly tted over the entire housing -I and the closure element 43. The lower end of the rubber sheath 45 extends vdown over a portion of the lead sheath 44 which encases the bulb 1. The rubber sheath 45 is formed of a size so that it will snugly iit the housing I, and associated parts and is stretched over the housing by means of a special tool which is not part of the present invention. Before the rubber sheath is entirely collapsed to snugly grip4 the thermostat, an

port being rotatabiy adjustable in saidtlireaded bore for axial displacement relative to said actu' ating element. and means carried by said support for frictionally engaging the threaded surface of the bore to retain the support in adjusted' positions.

3. A control switch comprising a housing hav- I actuating element, and lugs of vfri'ction material carried by and projecting beyond the threaded surface ofthe support fer frictionally engaging the threaded surface of the bore to retain the support in adjusted positions'.

4. A control switch-comprising a, housinghav ing a threadedv bore therein, a threaded support treadedly mounted in said bore` a switch assembly havingr a movable element and lcarri 1d by ysaid thread-ed support; an actuating element ferr-- tending into said b^re for actuating the movable.-

element of said switch assembly, said threaded support being rotatably adjustable in said tisread# ed bore for axial displacement relative to said actuating element, and a plate of friction material carried by said support and having portions projecting beyond the threaded surface of the support for frictionally engaging the threaded surface of the boreto retain the support in adjusted positions.

5. A control switch comprising a housing element heaving a bore therein the inner cylindrical surface of which is threaded, a support ele- `ment having a threaded external cylindrical surface threadedly mounted in said bore, a switch assembly having a movable element and carried by said threaded support, a thermostat carried by said housing and having a temperature responsive displaced member for actuating the movable element of the switch, said threaded support being rotatably adjustable in said threaded bore for axial displacement relative to said actuating element, and means carried by one element and frictionally engaging the threaded surface of the other to frictionally ,y restrain said elements against relative movement. i

6. A thermostat switch for use in battery charging comprising a tubular housing element, a thermostat having a body portion mounted in the housing and an extension projection beyond the end of the housing for insertion in the electrolyte' of a battery t0 be charged, a movable member on said thermostatxtending into said tubular housing, the inner surface of said housing element being threaded, a support element heaving a threaded external cylindrical surface threadedly Jmounted in the threaded portionof said housing element, a switch assembly having a `movable member and carried by said threaded support element, said threaded support element being rotatably adjustable in said threaded bore for axial displacement of the latter relative to said actuating member, and means carried by one element and frictionally engaging the threaded surface of the other to frictionally restrain said elements against relative movement.

7. A thermostat switch for use in battery charging comprising a tubular housing element, a thermpstat having a body portion mounted in the housing andan extension projection beyondthe end of the housing for insertion in the electrolyte of a battery to be charged, a movable member on said thermostat extending into said tubular housing, the inner surface of said housing element being threaded, a support element having a threaded external cylindrical surface threadedly mounted in the threaded portion of said housing element, a switch assembly having a movable member and carried by said threaded support element, said threaded support element being rotatably adjustable in said threaded bore for axial displacement relative to said actuating member, and means carried by said support element for frictionally engaging the threaded surface of the housing element to retain the support in adjusted positions.

8. A thermostat switch for use in battery charging comprising a tubular housing element, a thermostat having a body portion mounted in the housing and an extension projection beyond the end of the housing for .insertion in the electrolyte of a battery t0 be charged, a movable member on said thermostat extending into said tubular housing, the inner surface of said housingelement being threaded, a support element having a thread`` -ed .external cylindrical surface threadedly mounty ed in the threaded portion of-said housing element, a switch assembly 'having a movable member and carried by said threaded support ele- 75 ment, said threaded support element being rotatably adjustable in said threadedbore for axial displacement relative to said actuating member, and lugs of friction producing material carried by and projecting beyond the threaded surface of the support for frictionally engaging the threaded inner surface of the housing element to retain the support in adjusted positions.

9. A thermostat switch for use in battery charging comprising a tubular housing element, a thermostat having a body portionl mounted in the housing and a bulb projecting beyond the end of the housing for insertion in the electrolyte of a battery to be charged, a movable member on said thermostat extending into said tubular housing, the inner surface of said housing element being threaded, a support element having a threaded external cylindrical surface threadedly mounted in the threaded portion of said housing element, a switch assembly having a movable member and carried by said threaded support element, said threaded support element being rotatably adjustable in said threadedbore for axial displacement relative to said actuating member, and a plate of friction4 material carried by said support and having portions projecting beyond the threaded surface of the support for frictionally engaging the threaded inner surface of the housing to frictionally retain the support in adjusted positions.

10. An apparatus for adjusting a control switch having a housing element provided with a bore therein the inner cylindrical surface of which is threaded, a support element havingr a threaded external cylindrical surface threadedly mounted in said bore, a switch assembly having fixed and movable contact members and a terminal for each contact member carried by said support element, an actuating member carried by said housing for actuating the movable member of said switch assembly, said threaded support element being rotatably adjustable in said threaded bore for axial displacement relative to said actuating member, means carried by one element and frictionally engaging the threaded surface of the other to frictionally restrain said elements against rela- 'tive movement, said apparatus comprising a tool havinginsulated contacts for engaging the terminals on said support element for adjusting the position of the latter, and means for indicating whether the contact members are closed or separated. 4

li. An apparatus for adjusting a control switch having a housing element provided with a bore therein the inner cylindrical surface of which is threaded, a support element having a threaded externai cylindrical surface threadedly ymounted in said bore, a switch assembly having 'xed and movable contact members and a terminal for each contact membercarried by said support element, an actuating member carried by said housing for actuating the movable member of said switch assembly, said threaded support element being rotatably adjustable in-said threaded bore for axial displacement relative to said actuating member, means carried by one element and frictionally engaging the threaded surface of the other to frictionally restrain said elements Lagainst relative movement, said apparatus comprising a tool having insulated contacts for engaging the terminals on said support'element for adjusting the position of the latter, and a circuit inciuding a source of electrical energy and an electric indica-tor connected across said in,-v

sula'ted contacts and adapted to be completed by the closure of said contact members.

o asvaose 5 i 12. in apparatus for adjusting a control switch having a housing clement provided with a hore therein the inner cylindrical surface of which is threaded, a slingert element having a threaded external cylindrical surface threadedly mounted in said bore, a switch assembly having fixed and movable contact members and a terminal for each contact member carried by said support element,

an actuating member carried by said housing for actuating the movable member of said switch ase semblv, said threaded support element being rotatably adjustable in said threaded bore for axial displacement of Vthe latterrelative to said actuating member, means carried by one element 'and frictionally engaging the threaded surface of n 13. A temperature controlling device for use in battery chargers, said device comprising a housing open atboth ends, a thermostatic mein ber having a body portieri secured in one of said Y open ends, a bulb containing an expansibie fiuid formeel on one side of said. member and extending beyond said housing for insertion into the elec trolyte of a battery under charge, a switch unit having a fixed .and movable contactdisposed in the other end of said housing, said. contacts .being normally closed, actuating means formed on the other side of said member and extending into said housing to a position adjacent said movable contact, said switch being movable axially in said housing for varying the position of the movable contact' relative to said actuating means to thereby contrai the temperature at which a battery may he charged, and means carried by said switch for irictionally engaging the housing for retaining the switch in its adjusted position.

BENJAMIN F. W. HEYER. 

